I'm starting a new story and the most jarring change is that i know so little about it, which has left me stuck since i tend to make the most progress when I bonce my ideas off each other. Since I'm taking a break from my larger story that I've been working on since 2017; I'd like to take a different approach and give plotting a try instead of pantsing it like always. So think think i might want some advice on how to do that. This story's a deconstruction of the collectable monster subgenre. and the protagonist's who inhabit it tend to be rather simple, single minded and young. which is another attribute that gives me whiplash since my last protagonist was very complex and i knew a lot about her. though i remember she started out with a very simple idea behind her. I don't know much about him besides the fact he wants to be "the master" is oblivious to many of the darker aspects of the world he inhabits, and is reasonably good hearted. i don't know what would make his desire "to be the master" stand out or be unique since it's something shared by most of the inhabitants of the world.
Sounds like you have the start of a story, let the search begin you have the starting and what he wants...……….go for it.
That sounds like one of those stories where the side characters might be more interesting than the main. "Megaman syndrome" I call it. Anyway, think about the ways people could oppose your MC. If MC is good, what are some of the ways a person might be bad in this universe? Also, frankly it sounds a lot like pokemon, so I think you need to focus on worldbuilding first. What makes your world unique? After that, follow up with "what kind of people live in this world?"